Many buildings or structures include pneumatic tube transport systems for transporting objects, such as products, components, documents, drawings or other materials from one location in the building to another. Pneumatic tube transport systems typically comprise a number of substantially hermetically sealed tubes extending between locations in a building and a mechanism for selectively evacuating air from, or forcing air into, the tubes. In use, objects are placed in a carrier vessel, typically a substantially cylindrical housing, which is placed into the pneumatic tube transport system. The vessel is then propelled through the tube by creating a zone of relatively higher pressure on one side of the carrier vessel than on the other. This may be accomplished by creating a zone of negative pressure (e.g. a vacuum) in front of the vessel or by creating a zone of positive pressure behind the vessel.
In certain settings, the objects include containers housing fluids that need to be transported using the pneumatic tube transport system. For example, in the health care setting pneumatic tube transport systems are well adapted for transporting fluids such as laboratory samples, blood samples or other body fluids, or intravenous bags between areas of the building. However, when using pneumatic tube transport systems in the health care field, it is critical that the carrier vessels be suitable for transporting fluids. More particularly, it is necessary that the carrier vessels, upon closure, seal to provide substantially leak-proof containment of fluids, which may unwantedly spill from their primary containers into the vessel. Fluids which spill from their primary containers inside the vessel may leak from the vessel into the pneumatic tube posing a health risk and resulting in a risk that the pneumatic tubes may not properly function due to the presence of fluid in the system.